Flowserve DFC17 - Manual (Page 4)

4 DataFlo Digital Electronic Controller DFC17 Installation, Operation and Maintenance Instructions WCAIM2026
1.0 GENERAL
1.1 Basic Design
The Worcester/McCANNA DataFlo Digital Electronic Controller
(DFC17) was designed for use with the Worcester/McCANNA
Series 75 electric actuators. However, it may also be used with
other actuators or electrically operated rotary devices, provided
the specified load parameters as given in Section 5.3 are not
exceeded.
CAUTION: This controller is sensitive to electrical noise;
please see Section 1.2
PLEASE READ THIS SECTION
A. The 4–20 mA Setpoint signal input circuit of both the AC
and DC Digital Controller board is protected with a 62 mA
fuse (F1). The fuse is used to protect the input circuit
from an excessively high voltage. The fuse used in the
input circuit is a Littlefuse PICO II very fast-acting fuse
rated at 62 mA.
All DC Digital Controller boards also use a standard 1 1 /
4
",
250 volt, 3 amp fuse (F2) to protect the circuit board and
the power source in case of a fault in the DC motor driver
integrated circuit on the circuit board.
CAUTION: It is important that the DC voltage power
source be connected properly to the actuator’s terminal
strip. Terminal one (1) of this strip is to have the
negative or common wire connected to it. Terminal two
(2) is to have the positive wire connected to it.
Note: All wiring to terminal strip should be inserted only
to mid-point of terminal strip.
For 240 VAC Digital Controller only, limit switches do not
directly control the motor(s). Therefore, the actuator will
not stop when the limit switches trip. Use care not to
drive the actuator past its normal limits.
B. The Digital Controller board requires both a setpoint input
signal and a process input signal.
C. The Digital Controller board can be set up in several ways
for normal operation. The board is designed to control in
90° quadrants only (with alternate potentiometer gearing,
180° of rotation is available). The number of quadrants
over which the board will control is determined by the
number of teeth on the feedback pot pinion gear.
D. Quite often when we receive an actuator for repair, we
find that the only thing wrong with the unit is that the
feedback potentiometer is out of calibration. It is very
important that the feedback pot be properly calibrated for
correct operation of the Controller board. It is also very
important that the actuator shaft not be rotated out of the
quadrant for which the feedback potentiometer has been
calibrated. Whenever you have a problem with the
Controller calibration, always check the feedback
potentiometer calibration first. See paragraph 6.3.6 in the
troubleshooting section.
1.2 Environmental Considerations
CAUTION: The DataFlo Digital Electronic Controller is sensitive
to electrical noise on signal, process, or supply lines and in
the environment. For maximum controller sensitivity, the
electrical noise level should be as low as possible. Follow
installation and calibration guidelines carefully and use
shielded wire as stated in paragraph 1.2.3.
Flowserve recommends that all products which must be stored
prior to installation, be stored indoors, in an environment
suitable for human occupancy. Do not store product in areas
where exposure to relative humidity above 85%, acid or alkali
fumes, radiation above normal background, ultraviolet light,
or temperatures above 120°F or below 40°F may occur. Do not
store within 50 feet of any source of ozone.
Temperature and humidity are the two most important factors
that determine the usefulness and life of electronic equipment.
Flow Control Division
Worcester Actuation Systems
Quadrants of Operation